This is a note to let you know that I've just added the patch titled
usb: typec: ucsi: displayport: Fix potential deadlock
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
usb-typec-ucsi-displayport-fix-potential-deadlock.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From b791a67f68121d69108640d4a3e591d210ffe850 Mon Sep 17 00:00:00 2001
From: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
Date: Tue, 7 May 2024 16:43:16 +0300
Subject: usb: typec: ucsi: displayport: Fix potential deadlock
From: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
commit b791a67f68121d69108640d4a3e591d210ffe850 upstream.
The function ucsi_displayport_work() does not access the
connector, so it also must not acquire the connector lock.
This fixes a potential deadlock scenario:
ucsi_displayport_work() -> lock(&con->lock)
typec_altmode_vdm()
dp_altmode_vdm()
dp_altmode_work()
typec_altmode_enter()
ucsi_displayport_enter() -> lock(&con->lock)
Reported-by: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>
Fixes: af8622f6a585 ("usb: typec: ucsi: Support for DisplayPort alt mode")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20240507134316.161999-1-heikki.krogerus@xxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/usb/typec/ucsi/displayport.c | 4 ----
1 file changed, 4 deletions(-)
--- a/drivers/usb/typec/ucsi/displayport.c
+++ b/drivers/usb/typec/ucsi/displayport.c
@@ -249,8 +249,6 @@ static void ucsi_displayport_work(struct
struct ucsi_dp *dp = container_of(work, struct ucsi_dp, work);
int ret;
- mutex_lock(&dp->con->lock);
-
ret = typec_altmode_vdm(dp->alt, dp->header,
dp->vdo_data, dp->vdo_size);
if (ret)
@@ -259,8 +257,6 @@ static void ucsi_displayport_work(struct
dp->vdo_data = NULL;
dp->vdo_size = 0;
dp->header = 0;
-
- mutex_unlock(&dp->con->lock);
}
void ucsi_displayport_remove_partner(struct typec_altmode *alt)
Patches currently in stable-queue which might be from heikki.krogerus@xxxxxxxxxxxxxxx are
queue-5.10/usb-typec-ucsi-displayport-fix-potential-deadlock.patch
